Helium nanodroplets and trapped Bose-Einstein condensates as prototypes offinite quantum fluids

Helium nanodroplets and trapped Bose-Einstein condensates in dilute atomic gases offer complementary views of fundamental aspects of quantum many-body systems. We discuss analogies and differences, stressing their common theo retical background and peculiar features. We briefly review some relevant c oncepts, such as the meaning of superfluidity in finite systems, the behavi or of elementary excitations and collective modes, as well as rotational pr operties and quantized vorticity. (C) 2001 American Institute of Physics.